The invention relates to a device for changing the position of a functional element in an electrical apparatus, in particular the head-mounting plate in a magnetic-tape apparatus, the functional element being movable between a rest position and two-spaced apart operating positions, i.e. a first and a second operating position, and the functional element, which is spring loaded towards its rest position, being held electro-magnetically in the first operation position.
In magnetic-tape equipment intended for playing back tape cassettes, in particular Compact Cassettes, it is known to move the magnetic head relative to the magnetic tape in the cassette. For this purpose the magnetic head is arranged on a head-mounting plate, which is electro-mechanically movable. In a rest position the head-mounting plate is positioned in such a way that the magnetic head is completely withdrawn from the tape; in a first operating position or play position the head-mounting plate is positioned in such a way that the magnetic head is fully in contact with the tape; and in an intermediate position between the first operating position and the rest position the magnetic tape can be moved past the head substantially without any contact. This second operating position is referred to as the Cue or MSS position.
From DE-AS No. 29 10 343 it is known to keep the head-mounting plate in the rest position by means of a spring. If the head-mounting plate is to be set to the first operating position an electromagnet is energised to pull the head-mounting plate into the first operating position via a lever mechanism. From this first operating position the head-mounting plate can return to the rest position via a latching device at the location of the second operating position if the first magnet is de-energised and the latching device is released by a second electromagnet. If the second electromagnet does not release the latching device the head-mounting plate remains in the second operating position.